A skin lesion: Polymorphous or Multiform Erythema.
It is a skin condition of unknown cause; it is a type of lesion possibly mediated by the deposition of immune complexes in the superficial microvasculature of the skin and the oral mucous membrane that generally follows an infection or exposure to the drug.
It is an uncommon disorder, with a maximum incidence in the second and third decades of life. The disorder has several forms or presentations, hence its name reflects it (multiform, “multiform”, in various ways).
Injuries are a typical manifestation of it. Two types are recognized, one mild to moderate and the other severe (erythema multiforme minor and erythema multiforme greater).
Signs and symptoms
The condition varies from a mild, self-limited skin rash (Erythema multiforme minor) to a severe and life-threatening form known as erythema multiforme, which also affects the mucous membranes.
There are usually no prodromal symptoms in minor erythema multiforme. However, major erythema multiforme may be preceded by mild symptoms, such as fever or chills, joint weakness or pain.
Usually, in erythema multiforme, few or hundreds of skin lesions appear within a 24-hour period.
Lesions are seen for the first time on the back of the hands and / or on the top of the feet, and then extend along the extremities towards the trunk.
The upper extremities are more commonly affected than the lower extremities. Palms and plants may be involved.
The face, neck and trunk are common places. Cutaneous lesions are often grouped on elbows and knees. There may be a mild associated itching or burning sensation.
The initial lesions are clearly demarcated, are round, red / pink and flat (macules), which rise (papules / palpable) and gradually enlarge to form plaques (flat and raised patches) up to several centimeters in diameter.
The center of the papule / plaque becomes darker in color and develops superficial (epidermal) changes such as blisters or crusting. The lesions usually evolve for 72 hours.
The typical lesion (also called iris lesion) of erythema multiforme has a sharp edge, regular round shape and three concentric color zones:
- The center is dark or dark red with a blister or scab
- The next ring is pale pink and rises due to edema (fluid swelling)
- The outermost ring is bright red.
- The atypical target lesions show only two zones and / or an indistinct edge.
The eruption is polymorphic (meaning it is in many forms), hence the ‘multiform’ in the name. The lesions may be in various stages of development with typical and atypical objectives present at the same time.
A complete skin examination may be required to find typical goals, since these may be few in number.
The lesions show the Köbner phenomenon (isomorphic), which means that they can develop in sites of anterior cutaneous trauma (but not simultaneous or later).
There is no associated swelling of the face, hands or feet, even though these are common sites of rash distribution. However, the lips are often swollen, especially in greater erythema multiforme.
Commitment of the mucous membrane
Mucosal lesions, if present, usually develop a few days after the skin rash begins.
In minor polymorphous or multiform erythema, the mucous membrane involvement is absent or mild.
Changes in the mucosa, if present, initially consist of redness of the lips and inside the cheek. Sometimes blisters develop and break up quickly to form erosions and ulcers.
In larger erythema multiforme, one or more mucous membranes are usually affected, most often the oral mucosa:
- More commonly lips, inside the cheeks, tongue
- Less commonly floor of the mouth, palate, gums.
Other affected mucosal sites may include:
- Anus and genitals
- Trachea / bronchi
- Gastrointestinal tract.
Mucosal lesions consist of swelling and redness with blistering.
The blisters break quickly and leave large, superficial, irregularly shaped and painful ulcers that are covered by a whitish pseudomembrane.
Usually, the lips are swollen with hemorrhagic scabs. The patient may have difficulty speaking or swallowing due to pain.
With mycoplasma pneumonia, mucous membranes may be the only affected sites (mucositis). This can be serious and require hospitalization due to the difficulty to eat and drink.
It has not been determined if this is a limited form of erythema multiforme. It is also known as Fuchs syndrome, and erythema multiforme of the mucosa may occasionally be due to recurrent herpes simplex.
Recurrent multiform erythema
Erythema multiforme can be recurrent, with multiple episodes per year for many years. It is believed that this is almost always due to HSV-1 infection.
How is the diagnosis of polymorph or multiform erythema made?
Erythema multiforme is a clinical diagnosis, although a skin biopsy may be required to exclude other conditions. The histology of erythema multiforme is characteristic but not diagnostic. It varies according to the age of the lesion, its appearance and the part of the biopsy.
Other tests may be done to look for infections commonly associated with erythema multiforme, such as mycoplasma.
- Smaller multiform erythema: smaller typical targets or elevated edematous papules distributed stubbornly.
- Erythema multiforme major: typical major objectives or elevated edematous papules acrally distributed with involvement of one or more mucous membranes; epidermal detachment involves less than 10% of total body surface area (ATSC)
- SJS – Stevens-Johnson Syndrom (Stevens Johnson Syndrome) / TEN – Toxic Epidermal Necrolysis (Toxic Epidermal Necrolysis): Generalized blisters that predominate on the trunk and face, presenting erythematous or pruritic macules and one or more erosions of the mucous membrane ; the epidermal detachment is less than 10% of the total surface area of the body for Stevens-Johnson syndrome and 30% or more for toxic epidermal necrolysis.
The mild form usually presents with mild itching (but the itching can be very severe), pinkish-red spots, symmetrically arranged and starting at the extremities.
It often adopts the classic “target lesion” appearance, with a red-pink ring around a pale center. The resolution within 7-10 days is the norm.
Individuals with persistent polymorphous or multiform (chronic) erythema will often have a minor injury, scratch, or abrasion form within a week.
Irritation or even pressure from clothing will cause the pain of erythema to continue to spread along its margins for weeks or months, long after the original sore has healed in the center.
Who is affected by Polymorphic or Multiform Erythema?
Poliform erythema most often affects young adults (20-40 years of age), however, all age groups and races may be affected. There is a male predominance.
There is a genetic tendency to erythema multiforme. Certain types of tissues are found most frequently in people with erythema multiforme associated with herpes (HLA-DQw3) and recurrent erythema multiforme (HLA-B15, -B35, -A33, -DR53, -DQB1 * 0301).
Causes of Polymorphous Erythema
It has been reported that many suspected etiologic factors cause MS.
- Infections: Bacterial (including vaccination with Bacillus Calmette-Guérin (BCG), hemolytic streptococci, legionellosis, leprosy, Neisseria meningitidis, Mycobacteria, Pneumococcus, Salmonella species, Staphylococcus species, Mycoplasma pneumoniae), Chlamydia.
- Fúngico (Coccidioides immitis)
- Parasite (Trichomonas species, Toxoplasma gondii),
- Viral (especially Herpes Simplex)
- Reactions to medications, most commonly to: antibiotics (including, Sulfonamides, Penicillin), anticonvulsants (Phenytoin, barbiturates), Aspirin, antituberculous and Allopurinol and many others.
- Physical factors: radiotherapy, cold, sunlight
- Other: collagen diseases, vasculitis, non-Hodgkin lymphoma, leukemia, multiple myeloma, myeloid metaplasia, polycythemia
It is considered that the minor MS is being activated by the VHS in almost all cases. A herpetic etiology also accounts for 55% of the cases of major MS. Among the other infections, Mycoplasma infection seems to be a common cause.
It has been shown that the suppression of herpes simplex virus and even prophylaxis (with acyclovir) prevents the recurrent eruption of erythema multiforme.
Polymorph or multiform erythema is often self-limiting and does not require treatment. The appropriateness of glucocorticoid treatment may be uncertain, because it is difficult to determine if the course will be resolutive.
Treatment may be required for any possible cause, such as oral acyclovir (non-topical) for HSV or antibiotics (eg, erythromycin) for Mycoplasma pneumoniae. If a cause of a medication is suspected, the possible offensive medication should be discontinued.
Supportive / symptomatic treatment may be necessary.
Itching: oral antihistamines and / or topical corticosteroids can help.
Oral pain: mouth rinses containing local anesthetic and antiseptic reduce pain and secondary infection.
The participation of the eyes should be evaluated and treated by an ophthalmologist.
Erythema poliformo mayor may require hospital admission for supportive care, particularly if severe oral involvement restricts alcohol consumption.
The role of oral corticosteroids remains controversial, as no controlled study has shown any benefit. However, for severe disease, a measure of 0.5-1 mg / kg / d of prednis (ol) is often used early in the disease process.
Recurrent erythema multiforme is usually treated initially with continuous oral acyclovir for 6 months at a dose of 10 mg / kg / d in divided doses (eg, 400 mg twice daily), even if HSV has not been a trigger obvious for the patient’s erythema multiforme.
This has been shown to be effective in double-blind, placebo-controlled studies. However, erythema multiforme may reappear when acyclovir is stopped.
Other antiviral medications such as valciclovir (500-1000 mg / d) and famciclovir (250 mg twice daily) should be tried if acyclovir has not helped.
Other treatments (used continuously) that have been reported to help suppress recurrent erythema multiforme include:
- Dapsone 100-150 mg / day
- Antimalarial drugs (eg, Hydroxychloroquine)
- Azathioprine 100-150 mg / day
- Other: Thalidomide, Cyclosporine, Mycophenolate Mofetil, Photochemotherapy (PUVA)
What is the prognosis for erythema multiforme?
Minor polymorphous erythema usually resolves spontaneously without leaving scars for 2 to 3 weeks. Erythema multiforme may take up to 6 weeks to resolve. Erythema multiforme does not progress to SJS / TEN.
There may be a residual discoloration of the mottled skin. Significant ocular involvement in larger polymorphous erythema can rarely lead to serious problems, including blindness.